The effect of contingency analysis on the nodal prices in the day-ahead market

We look at the effect of modeling branch-outage contingencies on locational marginal prices. To model contingencies in the day-ahead auction, we formulate a two-stage stochastic program. Rather than follow the current practice of including a list of possible contingencies that must be satisfied, we incorporate a larger set of contingencies in the model and allow contingencies to result in load reductions/outages at a cost. The model can be used and interpreted in two ways. One is to look at the tradeoff between reliability and outage costs. Another is to consider the load losses resulting from a contingency to be consumer offers of load reductions in response to line outages as part of the day-ahead auction. In analyzing the model structure, we find that the prices in the model closer in definition to those currently used in the day-ahead auction do not maximize expected surplus because the day-ahead auction produces prices that assume shortages will never occur. This raises issues with the design of auctions with important stochastic elements in the market. We present results for a 68-node grid with 86 branches (lines and transformers) to illustrate how prices and expected values change as the costs of outages are varied.     

The role of personal dexterity and incentive gamification to enhance employee learning experience and performance

Cognition, Technology & Work - This paper aims to develop a concept of incentive gamification for organizations in the digital era. Incentive gamification is an incentive-based policy using the...     

Kinetic evaluation of an oligomeric amidation reaction

Homopoly(amides) similar to those of liquid crystalline poly(oxybenzoate) were prepared by acidolysis of the monomer p-acetamidobenzoic acid. The kinetics of catalyzed and uncatalyzed acidolysis of the 4-acetamidobenzoic acid were investigated at 265, 275, and 285°C. A second-order rate model, which can analyze kinetic parameters of two different kinetic regimes, was used to interpret the experimental data for 18 different experimental sets. It is observed that the correlation coefficient between observed and calculated values range between 0.98 and 0.99, confirming the validity of the stated model. The nature of the kinetic behavior in the two regimes was found to be independent of both catalyst type and concentration. In effect second-order rate law adequately describes the entire kinetic behavior of this system. The Arrhenius constants and activation energy parameters for this system have been reported. Differential scanning calorimetry (DSC) results of the oligomers indicate that the homopoly(amides) melt around 360°C with degradation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2534–2543, 2001     

Minimum Mean-Square Error Timing Recovery Schemes for Digital Equalizers

Two algorithms are presented for optimum timing recovery in digitally implemented equalizers. The first one is a polarity-type algorithm based on the conventional minimum mean-square error criterion. A theoretical analysis is made to characterize the algorithm phase detector and evaluate its steady-state phase jitter variance. Influence of various channel and system design parameters on the algorithm performance is illustrated using phase jitter probability densities obtained by means of computer simulations. Interaction of the algorithm with decision-directed carrier recovery is also examined. It is shown that interaction with carrier recovery may considerably degrade the timing acquisition performance, and a second algorithm is then presented which eliminates this interaction. The second algorithm is based on the minimization of a modified mean-square error criterion which provides a measure of the intersymbol interference, independently of the carrier phase. Decision-directed timing and carrier recoveries are thus decoupled and the system startup period is considerably reduced. Phase detector characteristic and steady-state jitter performance of the second algorithm are evaluated by analytical means and computer simulations, as in the first algorithm.     

Sensory education decreases food neophobia score and encourages trying unfamiliar foods in 8–12-year-old children

The effects of sensory education on food-related traits and responses to food were examined over a period of 1.5 years in school children. Children (N = 164, 8- and 11-year-old at baseline) from two schools in Helsinki were divided in an education group (E; N = 92) receiving up to two waves of sensory lessons, and a control group (C; N = 72) participating in baseline and follow-up measurements only. The 1st wave (10 lessons) followed the principles of the French program “Classes du goût” and the 2nd wave (5 extensive lessons to 2/3 of the E group) concentrated on different food categories. A questionnaire assessing children’s liking and familiarity of unfamiliar and familiar foods and food neophobia, was sent to parents at the baseline and after each wave of sensory lessons. After education, the E group had tried a larger proportion of unfamiliar foods than at the baseline. The number of tasted foods in the C group remained at the baseline level. Food neophobia score decreased in the E group, while no change was seen in the C group. The effects of education were stronger in the younger children. Thus, sensory education has potential to activate children to try new foods and thereby to increase variety in their diets.     

Ageing study of Cu–Al–Be hypoeutectoid shape memory alloy

Thermal ageing at constant temperature (350 °C) and under systematically designed temperature-varying conditions were performed on the metastable austenitic phase of hypoeutectoid Cu–Al–Be shape memory alloy. Thermal precipitations and their effects on the alloy global microstructure were studied by DSC, XRD and SEM techniques. Precipitations of equilibrium phases (α + γ₂) within the temperature range of 330–370 °C, and their generalization by a discontinuous mechanism for an ageing time of 864 ks (240 h), were identified and analyzed. The results of this study are expected to benefit the applications of copper-based shape memory alloys under various thermal conditions.     

Preparation and thermal energy storage properties of poly(n‐butyl methacrylate)/fatty acids composites as form‐stable phase change materials

This work is focused on the preparation, characterization, and determination of thermal energy storage properties of poly(n‐butyl methacrylate) (PnBMA)/fatty acid composites as form‐stable phase change material (PCM). In the composite materials, the fatty acids act as latent heat storage material whereas PnBMA serves as supporting material, which prevents the leakage of the melted fatty acids. The maximum encapsulation ratio for all fatty acids was found to be 40 wt%. The composites that do not allow PCM leakage in melted state were identified as form‐stable PCMs. The compatibility of fatty acids with PnBMA is investigated by optical microscopy (OM) and Fourier Transform Infrared (FT‐IR) spectroscopy. Thermal properties and thermal reliability of the form‐stable composite PCMs were determined using differential scanning calorimetry (DSC). DSC analysis revealed that the form‐stable composite PCMs had melting temperatures between 29.62°C and 53.73°C and latent heat values between 67.23 J/g and 87.34 J/g. Thermal stability of the composite PCMs was studied by thermal gravimetric (TG) analysis and the results indicated that the form‐stable PCMs had good thermal stability. In addition, thermal cycling test showed that the composite PCMs had good thermal reliability with respect to the changes in their thermal properties after accelerated 5,000 thermal cycling. On the basis of all results, it was also concluded that the prepared form‐stable composite PCMs had important potential for many thermal energy storage applications such as solar space heating of buildings by using wallboard, plasterboard or floors integrated with PCM. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers     

Polyindene/organo‐montmorillonite conducting nanocomposites. I. Synthesis,characterization, and electrokinetic properties

In this study, Na‐montmorillonite was organically modified with cetyltrimethylammoniumbromide (CTAB) and intercalated with in‐situ polymerized indene. Polyindene(PIn)/Organo‐MMT nanocomposites were obtained with three different compositions and coded as: K1: [PIn(94.5%)/O‐MMT(5.5%)], K2: [PIn(92.8%)/O‐MMT(7.2%)], and K3: [PIn(87.9%)/O‐MMT(12.1%)]. These nanocomposites were subjected to full characterization with various techniques. Electrokinetic studies were conducted to reveal the zeta (ζ)‐potential characteristics of the nanocomposites. ζ‐potentials of the materials were observed to decrease with increasing O‐MMT content. The cationic (CTAB) and anionic (sodium dodecylsulfate) surfactants were shifted the ζ‐potentials of the colloidal dispersions to more positive and more negative regions, respectively whereas nonionic surfactant (Triton X‐100) caused almost no change. The pH and temperature were observed to shift the ζ‐potential values of the nanocomposites to more negative and slightly more positive regions, respectively. With the addition of mono (NaCl), di (BaCl₂) and three (AlCl₃) valent salts, the ζ‐potential of the nanocomposites were shifted to more negative, more positive, and much more positive regions, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Development of the Ontogenetic Self-Regulation Clock

To date, there is no overarching proposition for the ontogenetic-neurobiological basis of self-regulation. This paper suggests that the balanced self-regulatory reaction of the fetus, newborn and infant is based on a complex mechanism starting from early brainstem development and continuing to progressive control of the cortex over the brainstem. It is suggested that this balance occurs through the synchronous reactivity between the sympathetic and parasympathetic systems, both which originate from the brainstem. The paper presents an evidence-based approach in which molecular excitation-inhibition balance, interchanges between excitatory and inhibitory roles of neurotransmitters as well as cardiovascular and white matter development across gestational ages, are shown to create sympathetic-parasympathetic synchrony, including the postnatal development of electroencephalogram waves and vagal tone. These occur in developmental milestones detectable in the same time windows (sensitive periods of development) within a convergent systematic progress. This ontogenetic stepwise process is termed “the self-regulation clock” and suggest that this clock is located in the largest connection between the brainstem and the cortex, the corticospinal tract. This novel evidence-based new theory paves the way towards more accurate hypotheses and complex studies of self-regulation and its biological basis, as well as pointing to time windows for interventions in preterm infants. The paper also describes the developing indirect signaling between the suprachiasmatic nucleus and the corticospinal tract. Finally, the paper proposes novel hypotheses for molecular, structural and functional investigation of the “clock” circuitry, including its associations with other biological clocks. This complex circuitry is suggested to be responsible for the developing self-regulatory functions and their neurobehavioral correlates.